Chiral low-energy constants: Status and prospects

Abstract

Chiral low-energy constants (LECs) carry the information of short-distance dynamics involving heavier degrees of freedom not present in the chiral Lagrangian. Our knowledge of the LECs is all-important at phenomenological level because their relevance in the prediction of hadronic observables at low-energies and, on the other side, because they provide hints on the construction of a dual theory of QCD in the low-energy regime. I review briefly the status of these important couplings.